An attacker with the ability to write files to an insecure custom installation directory could place a malicious DLL that may be loaded by the application due to the Windows DLL search order.
"}],"value":"An attacker with the ability to write files to an insecure custom installation directory could place a malicious DLL that may be loaded by the application due to the Windows DLL search order."}],"credits":[{"lang":"en","type":"reporter","value":"Zabbix wants to thank Kazuma Matsumoto of GMO Cybersecurity by IERAE, Inc. for finding and reporting this issue."}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"When Zabbix Agent was installed on Windows into a custom installation directory, the installer did not verify whether the selected directory had secure access permissions. If the target directory allowed unauthorized users to modify its contents, an attacker could place a malicious DLL that could later be loaded by the application, resulting in DLL sideloading. The installer has been hardened to detect potentially unsafe installation directories and now requires explicit user confirmation before proceeding with installation in such locations. This reduces the risk of accidental installation into directories with inappropriate permissions while preserving compatibility with existing deployment scenarios.
"}],"value":"When Zabbix Agent was installed on Windows into a custom installation directory, the installer did not verify whether the selected directory had secure access permissions. If the target directory allowed unauthorized users to modify its contents, an attacker could place a malicious DLL that could later be loaded by the application, resulting in DLL sideloading. The installer has been hardened to detect potentially unsafe installation directories and now requires explicit user confirmation before proceeding with installation in such locations. This reduces the risk of accidental installation into directories with inappropriate permissions while preserving compatibility with existing deployment scenarios."}],"impacts":[{"capecId":"CAPEC-471","descriptions":[{"lang":"en","value":"CAPEC-471: DLL Search Order Hijacking"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"LOCAL","baseScore":5.4,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"PASSIVE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-427","description":"CWE-427: Uncontrolled Search Path Element","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-18T12:21:29.618Z","orgId":"72de3e22-0555-4a0d-ae81-9249e0f0a1e8","shortName":"Zabbix"},"references":[{"url":"https://support.zabbix.com/browse/ZBX-28077"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Update the affected components to their respective fixed versions.
"}],"value":"Update the affected components to their respective fixed versions."}],"source":{"discovery":"EXTERNAL"},"title":"Improper validation of custom installation directories on Windows could allow installation into locations with unsafe permissions, increasing the risk of DLL sideloading.","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Install the Zabbix Agent into directories with appropriately restricted access permissions. Verify and adjust permissions on custom installation directories to prevent unprivileged users from modifying their contents.
"}],"value":"Install the Zabbix Agent into directories with appropriately restricted access permissions. Verify and adjust permissions on custom installation directories to prevent unprivileged users from modifying their contents."}],"x_generator":{"engine":"Vulnogram 1.0.4"}}},"cveMetadata":{"assignerOrgId":"72de3e22-0555-4a0d-ae81-9249e0f0a1e8","assignerShortName":"Zabbix","cveId":"CVE-2026-59781","datePublished":"2026-08-18T12:21:29.618Z","dateReserved":"2026-07-07T08:30:49.859Z","dateUpdated":"2026-08-19T03:55:56.294Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-18 13:17:25","lastModifiedDate":"2026-08-19 04:17:27","problem_types":["CWE-427","CWE-427 CWE-427: Uncontrolled Search Path Element"],"metrics":{"cvssMetricV40":[{"source":"security@zabbix.com","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","baseScore":5.4,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-18T00:00:00+00:00","id":"CVE-2026-59781","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"59781","Ordinal":"1","Title":"Improper validation of custom installation directories on Window","CVE":"CVE-2026-59781","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"59781","Ordinal":"1","NoteData":"When Zabbix Agent was installed on Windows into a custom installation directory, the installer did not verify whether the selected directory had secure access permissions. If the target directory allowed unauthorized users to modify its contents, an attacker could place a malicious DLL that could later be loaded by the application, resulting in DLL sideloading. The installer has been hardened to detect potentially unsafe installation directories and now requires explicit user confirmation before proceeding with installation in such locations. This reduces the risk of accidental installation into directories with inappropriate permissions while preserving compatibility with existing deployment scenarios.","Type":"Description","Title":"Improper validation of custom installation directories on Window"}]}}}